The ultimate objective of the research projects in this application is to improve our understanding of mechanisms of disease in human myeloid leukemias, and to explore new therapeutic options relating to the disease pathways under investigation. It is anticipated that the laboratory and murine will inform the clinical project, and that the clinical insights will feed back to the animal and laboratory projects for further assessment. Members of the Biostatistics core will provide assistance to all the research projects contained in this program. The specific aims of Core C Biostatistics are: 1. To provide biostatistical collaboration for clinical research protocols. This includes all aspects of the design, conduct, analysis, and reporting of the clinical studies. 2. To provide biostatistical collaboration for the laboratory research studies. This includes all aspects of the design, conduct, analysis, and reporting of such studies, as well as the analysis of laboratory results in conjunction with, or as outcomes of, the clinical studies of Project 5. 3. To provide biostatistical collaboration for animal studies, including all aspects of the design and analysis of such studies. 4. To assist in the oversight of data management, other clinical support services, and the tracking of samples to Projects for analysis with data returned and computerized for statistical analysis.